"Castle Geyser has a unique, large, tall geyserite cone structure that may be reminiscent of a castle. This large structure is possibly due to trees growing in the area years prior that became coated in sinter and allowed the height to build up. Layers of geyserite cascade in step-like terraces from the geyser vent and continues to cover the surrounding area. Due to this amount of fragile sinter and the height of the cone, the water is inaccessible for scientific measurements. The western side of Castle Geyser appears smoother than the sinter steps on the east side. As the story goes, thermophile mats use to live on the cone but were peeled off by visitors, permanently damaging the cone structure. Now the water flows down the east side and no thermophiles are visible. The cone of Castle Geyser is thousands of years old and rests upon even older platforms. Together, they form one of the largest sinter formations in the world. Castle currently erupts, on average, every 14 hours. The water eruption frequently reaches 75 feet (24 m) and lasts about 20 minutes, followed by a noisy steam phase of 30-40 minutes."